Chassis control technology has achieved noteworthy progress, thanks to advancements in sensing and computing technologies as well as advances in estimation and control theory. This has permitted the design of various control systems using active means to maneuver the vehicle. One such enhancement is the control and adjustment of the tire forces through a braking force distribution control strategy, using a steering angle sensor, a lateral accelerometer, and a yaw rate sensor to enable a yaw rate feedback control.
The measured values of both lateral acceleration and steering angle are influenced by the bank angle of the road surface; the lateral accelerometer senses a bank-related component of gravity force, and the measured steering angle includes a bank-related steering correction necessary to maintain the intended travel path. It is known, as described in the U.S. Pat. No. 5,720,533 to Pastor et. al., issued on Feb. 24, 1998, and assigned to the assignee of the present invention, that a bank angle compensation term can be computed as a function of the measured lateral acceleration and yaw rate if steady state operating conditions are assumed. Additionally, the compensation can be estimated as a function of yaw rate error in systems that lack a lateral accelerometer, as described in U.S. Ser. No. 09/134954, filed on Aug. 17, 1998, now U.S. Pat. No. 6,112,147 also assigned to the assignee of the present invention. What is desired is a method of compensating a vehicle yaw rate control for operation on a banked surface during both transient and steady state operating conditions.